The present invention relates to a blood sampling device which samples blood from subcutaneous blood vessels, and particularly relates to one which specifies the position of blood vessels using near-infrared rays.
A blood vessel position presenting apparatus which is one of former blood position specifying devices is described with reference to FIG. 11. The blood vessel position presenting apparatus is a device capable of confirming the position and the direction of blood vessels.
The blood vessel position presenting apparatus of FIG. 11 is constituted including an image pick-up unit 101, an image processing unit 102, an illuminating unit 103, a display unit 104, a mark control unit 105, and a mark illuminating unit 106.
The illuminating unit 103 irradiates a living body with a near-infrared illumination light beam 127 which is an illumination light beam of a near-infrared wavelength region and is constituted including a near-infrared LED.
The image pick-up unit 101 takes a photograph of a living body and is, for example, a monochrome CCD camera or a monochrome CMOS camera having high spectral sensitivity from visible wavelength to near infrared wavelength region. The image pick-up information obtained from a reflected light beam 129 from a living body is transferred to the image processing unit 102 as a living body image information 121. The image pick-up unit 101 obtains a near-infrared image information which is living body image information when emitting the illumination light beam and a non-light image information which a living body image information when not emitting the illumination light beam, and then transfers the same to the image processing unit.
The display unit 104 displays an image based on an image information 124 output from the image processing unit 102 with a liquid crystal display or the like.
The mark illuminating unit 106 emits a puncture mark projecting light beam 128 for projecting a puncture mark showing a puncture position to the surface of a living body and is constituted including a visible light laser. The mark illuminating unit 106 emits the puncture mark projecting light beam 128 at an illumination timing and in an illumination direction based on a drive signal 126 from the mark control unit 105.
The mark control unit 105 generates the drive signal 126 based on a instruction signal 122 from the image processing unit 102. The instruction signal 122 contains a deviation information of the display position of the puncture mark included in an image displayed on the display unit 104 and the target position of the puncture mark input from the outside. The mark control unit 105 generates the drive signal 126 for matching the display position of the puncture mark with the target position of the puncture mark utilizing this deviation information.
The image processing unit 102 generates a processed near-infrared image information in which a blood vessel image and an injection needle image are emphasized based on the near-infrared image information which is a living body image information when emitting an illumination light beam, and generates a processed non-light image information in which a puncture mark image is emphasized based on the non-light image information which is a living body image information when not emitting an illumination light beam. Then, the processed near-infrared image information and the processed non-light image information are synthesized to obtain a display image information.
The elements illustrated in FIG. 11 are stored in a predetermined case, and are disposed at a predetermined positional relationship with a living body whose blood vessel position is to be detected for use.
FIG. 12 illustrates a general view of an example of the blood vessel position presenting apparatus. FIG. 12 illustrates an example in which the blood vessel position presenting apparatus and a living body are not fixed, and a case 202 is supported by scaffolds 209 and 210. The scaffolds 209 and 210 stabilize the case 202 and an arm 201 whose blood vessel position is to be detected in a state where the case 202 and the arm 201 are separated at a predetermined interval and the apparatus is disposed in such a manner that the case 202 and the scaffolds 209 and 210 surround the arm 201.
The case 202 is provided, on the upper surface, with a liquid crystal display portion 203 constituting the display unit 104, a trackball 204 which moves a cursor 207 displayed on the liquid crystal display portion 203, and an input button 208 for setting the position, of the cursor 207 as a target position of a puncture mark. On the liquid crystal display portion 203 of FIG. 2, blood vessels 206 and the cursor 207 are displayed. Onto the surface of the arm 201, a puncture mark 205 in the shape of a spot is projected.
When using the blood vessel position presenting apparatus of FIG. 12, a doctor and a nurse move the cursor 207 for setting the target position of the puncture mark using the trackball 204 on the screen of the liquid crystal display portion 203, and then pushing the input button 208 to thereby fix the position, indicated by the cursor 207 as the target position of the puncture mark. The puncture mark 205 is a mark projected by the mark illuminating unit 106, and looks red to the naked eye. The puncture mark 205 indicates an arbitrary portion on the surface of the arm 201 in the initial state. When the target position is fixed by the cursor 207, a red visible light laser of the mark illuminating unit 106 changes the direction in such a manner that the position of the puncture mark 205 and the target, position (the position of the cursor at this time) are matched on an image taken by the image pick-up unit 101.
The image processing unit 102 receives the near-infrared image information obtained when the illumination unit 103 emits a near-infrared light beam and the non-light image information obtained when the illumination unit 103 does not emit a light beam as a living body image information 121 from the image pick-up unit 101. As an example, the two kinds of image information are alternately input in time division. Since the venous blood has high absorptivity of a near-infrared light beam, a blood vessel portion appears in black and an injection needle appears in white on the image based on the near-infrared image information. On an image based on the non-light image information, the puncture mark projected onto the arm 201 by a puncture mark projecting light beam 128 which is a visible light beam appears.